ISO: Birthday Celebration Ideas for 16 yr. old Boy

I have been very actively racking my brain and rummaging through my recipe collection trying to come up with something really nice, and very special for a boy's 16th birthday. I know with girls people throw "Sweet 16" parties, but 1) that name for a party doesn't work for a boy, and 2) my husband cringed when I mentioned the idea of a "sweet 16" party for our oldest son to my husband. LOL.

Here is what I have to work with:
1) 25-30 people will be invited
2) it's a summer party, and I want it to be held outside after dark.
3) he will not be getting his driver's license at 16 due to being homeschooled...he will have to keep his learner's permit until age 18 so a "car/driving" theme won't work.
4) he hate's sports, so a sport's themed party won't work.
5) He is an avid video game collector, so I'm thinking of going with a game theme.
6) MOM (me) has to do all of the cooking, decorating, and planning for this party.
7) There will be both adults and some younger children attending part of the party, some teenagers and possibly a 2 yr. old boy will be spending the night at my house for the equivalent of a slumber party. Having the 2 yr. old here is a bit of a dilemma, his parents are young and married. He's my nephew's son and MY son wants that nephew to spend the night which means that his wife and son would also have to stay over although I'm thinking about seeing if my MIL would want to watch her great grandson that night since she is my next door neighbor :)
8) The birthday boy is mostly a vegetarian, so things like hamburgers, hotdogs, etc. won't work.
9) This party has to come off on a budget of roughly $50-75 for decorations, food, beverages, etc. This means that even though this kid loves pizza, I can't order out to pizza hut. LOL.